Configuring Packet Capture

Packet capture is a tool that helps you to analyze network traffic and troubleshoot network problems. The packet capture tool captures real-time data packets traveling over the network, for monitoring and logging.

Packets are captured as binary data, without modification. You can read the packet information offline with a packet analyzer such as Ethereal or tcpdump.

If you need to quickly capture packets destined for or originating from the Routing Engine and analyze them online, you can use the J-Web packet capture diagnostic tool. For more information, see Capturing and Viewing Packets with the J-Web Interface.

Note: The packet capture tool does not support IPv6 packet capture.

You can use either the J-Web configuration editor or CLI configuration editor to configure packet capture. For more information about packet capture, see the JUNOS Policy Framework Configuration Guide.

This chapter contains the following topics.

• Packet Capture Support On Different Device Types
• Packet Capture Terms
• Packet Capture Overview
• Before You Begin
• Configuring Packet Capture with a Configuration Editor
• Changing Encapsulation on Interfaces with Packet Capture Configured
• Verifying Packet Capture